The present invention relates to an internal device arrangement, in particular for a passenger cabin for example in an aircraft.
It is known from the prior art that the electrically active component parts, such as lighting devices, for example, for the passenger cabin of an aircraft, a ship, a coach or the like are integrated in internal device elements, for example in the form of a supply unit (PSU: Passenger Service Unit or Passenger Seat Unit).
In order to represent a space-saving lighting device, light sources with small dimensions are preferably used. In order that the required luminous efficacy is achieved for illuminating the aircraft cabin, for example, such light sources, such as light-emitting diodes (LEDs) or mercury-free gas lamps, for example, have a high luminance. A certain proportion of the energy supplied or passed through is converted into thermal energy in virtually all types of electrical component parts. If the dimensions of the component part are small, this waste heat is concentrated over a small area. In general, the life of an electrical component part is reduced as the operating temperature increases. Therefore, it is necessary in particular in the case of miniaturized electrical component parts, such as LEDs for cabin lighting, for example, to dissipate the thermal energy which is incident in substantially punctiform fashion. Thus, firstly the temperature of the light source is kept low and secondly the surrounding component parts are protected from excessively high temperatures.
DE 10 2004 051 146 B4 discloses a lighting unit which has been inserted into the wall or ceiling panelling of a cabin in a passenger aircraft. One exemplary embodiment demonstrates how the waste heat produced at the light source can be dissipated by an additional heat sink in the form of a metal plate, which is kept spaced apart from the ceiling panelling by a spacer.
Although on the one hand such an additional heat sink is advantageous since the lightweight materials which are usually used for cabin panelling parts have poor thermal conductivity and are thus not suitable for cooling the electrical apparatus, on the other hand such a heat sink causes additional material consumption, an increased requirement for installation space and an increased weight.